package com.example.utils;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.UUID;

/**
 *
 * 上传工具类
 */
public class UploadUtils {

        private static final String TAG = "uploadFile";
        private static final int TIME_OUT = 10*1000;   //超时时间
        private static final String CHARSET = "utf-8"; //设置编码
        /**
         * android上传文件到服务器
         * @param file  需要上传的文件
         * @param RequestURL  请求的url
         * @return  返回响应的内容
         */
        public static String uploadFile(File file, String RequestURL){
            String result = null;
            String  BOUNDARY =  UUID.randomUUID().toString();  //边界标识   随机生成
            String PREFIX = "--" , LINE_END = "\r\n";
            String CONTENT_TYPE = "multipart/form-data";   //内容类型

            try {
                URL url = new URL(RequestURL);
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setReadTimeout(TIME_OUT);
                conn.setConnectTimeout(TIME_OUT);
                conn.setDoInput(true);  //允许输入流
                conn.setDoOutput(true); //允许输出流
                conn.setUseCaches(false);  //不允许使用缓存
                conn.setRequestMethod("POST");  //请求方式
                conn.setRequestProperty("Charset", CHARSET);  //设置编码
                conn.setRequestProperty("connection", "keep-alive");
                conn.setRequestProperty("Content-Type", CONTENT_TYPE + ";boundary=" + BOUNDARY);
                conn.connect();

                if(file!=null){
                    /**
                     * 当文件不为空，把文件包装并且上传
                     */
                    DataOutputStream dos = new DataOutputStream( conn.getOutputStream());
                    StringBuffer sb = new StringBuffer();
                    sb.append(PREFIX);
                    sb.append(BOUNDARY);
                    sb.append(LINE_END);
                    /**
                     * 这里重点注意：
                     * name里面的值为服务器端需要key   只有这个key 才可以得到对应的文件
                     * filename是文件的名字，包含后缀名的   比如:abc.png
                     */

                    sb.append("Content-Disposition: form-data; name=\"img\"; filename=\""+file.getName()+"\""+LINE_END);
                    sb.append("Content-Type: application/octet-stream; charset="+CHARSET+LINE_END);
                    sb.append(LINE_END);
                    dos.write(sb.toString().getBytes());
                    InputStream is = new FileInputStream(file);
                    byte[] bytes = new byte[1024];
                    int len = 0;
                    while((len=is.read(bytes))!=-1){
                        dos.write(bytes, 0, len);
                    }
                    is.close();
                    dos.write(LINE_END.getBytes());
                    byte[] end_data = (PREFIX+BOUNDARY+PREFIX+LINE_END).getBytes();
                    dos.write(end_data);
                    dos.flush();
                    /**
                     * 获取响应码  200=成功
                     * 当响应成功，获取响应的流
                     */
                    int res = conn.getResponseCode();
                    if(res==200){
                        InputStream input =  conn.getInputStream();
                        StringBuffer sb1= new StringBuffer();
                        int ss ;
                        while((ss=input.read())!=-1){
                            sb1.append((char)ss);
                        }
                        result = sb1.toString();
                        System.out.println(result);
                    }
                }
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return result;
        }
}
